1. Field of the Invention
An apparatus consistent with the present invention relates to a washing machine and, more particularly, to a washing machine in which steam and hot water are supplied into a washing tub, so as to rapidly increase the temperature of wash water.
2. Description of the Related Art
Drum type washing machines generally perform a laundry washing process through operations thereof for raising laundry, together with wash water, along a cylindrical rotating drum containing the laundry and wash water, and subsequently dropping the laundry and wash water, during rotation of the cylindrical rotating drum. An example of such a drum type washing machine is disclosed in Japanese Patent Laid-open Publication No. 2001-149685. This drum type washing machine is configured to perform a washing process using heated wash water.
The disclosed drum type washing machine includes a water tub for containing wash water, a rotating drum rotatably mounted in the water tub, and provided with through-holes for spin-drying at a peripheral wall thereof, and a heater for heating the wash water contained in the water tub. In a wash cycle of the drum type washing machine, washing of laundry is carried out as the rotating drum rotates within the water tub at a relatively low speed under the condition in which wash water and detergent have been supplied into the water tub. In order effectively to wash the laundry, the wash water is used in the wash cycle in a state of being heated by the heater.
However, such a conventional washing machine has a problem in that a great deal of time is required to heat the wash water to a desired wash temperature because a large amount of wash water supplied into the water tub is heated entirely by the heater, which is disposed at the bottom of the water tub, so that the overall wash time is increased.
Furthermore, the conventional washing machine involves a waste of wash water because the wash water fills even a heater case installed at the bottom of the water tub. Waste of energy is also caused by the fact that it is necessary to heat the water contained in the heater case.